Abstract

Lattice constant of Bi2Se3 and Sb2Te3 crystals is determined by x-ray powderdiffraction measurement in a wide temperature range. Linear thermal expansion coefficients (α) of the crystals are extracted, and considerable anisotropy between α|| and α⊥ is observed. The low temperature values of α can be fit well by the Debye model, while an anomalous behavior at above 150 K is evidenced and explained. Grüneisen parameters of the materials are also estimated at room temperature.

Received 12 September 2011Accepted 27 November 2011Published online 30 December 2011

Acknowledgments:

We would like to thank S. Zhou for helping with the chemical structure in Fig. 1(a). This work is supported by the DOE (DE-FG02-07ER46451). The XRD measurement was performed at the National High Magnetic Field Laboratory, which is supported by NSF Cooperative Agreement No. DMR-0654118, by the State of Florida, and by the DOE.